import unittest adds 0.250s to script launch time

This should not be imported at root level, since it adds a lot of initialization overhead without need.

git/objects/submodule/base.py

@@ -3,8 +3,6 @@
 import logging
 import os
 import stat
-
-from unittest import SkipTest
 import uuid
 
 import git
@@ -934,6 +932,7 @@ def remove(self, module: bool = True, force: bool = False,
                         rmtree(str(wtd))
                     except Exception as ex:
                         if HIDE_WINDOWS_KNOWN_ERRORS:
+                            from unittest import SkipTest
                             raise SkipTest("FIXME: fails with: PermissionError\n  {}".format(ex)) from ex
                         raise
                 # END delete tree if possible
@@ -945,6 +944,7 @@ def remove(self, module: bool = True, force: bool = False,
                     rmtree(git_dir)
                 except Exception as ex:
                     if HIDE_WINDOWS_KNOWN_ERRORS:
+                        from unittest import SkipTest
                         raise SkipTest(f"FIXME: fails with: PermissionError\n  {ex}") from ex
                     else:
                         raise